The present invention relates generally to farm implements and, more particularly, to a commodity tank for an air seeder.
An air seeder is an agricultural implement that is commonly used to plant usually a seed crop in a large field. Air seeders typically have centrally located hoppers for seed and fertilizer which distributes them through an air stream to individual seed rows. It is convenient to fill, easy to clean out and move. Any crop that can be grown from seeds—which might vary is size from oilseeds to corn, can be sewn by an air seeder.
The seed and fertilizer hoppers are usually carried on a large cart located behind or in front of the seeder. The air stream is created by a high capacity fan mounted on the cart which blows air through conduits (pipes) connecting the hoppers and the row units. Seed and fertilizer are metered out from the hoppers by a meter wheel that is turning in a ratio set by the operator for the proper seed rate or seed density. The seeds enter the pipe in the airstream and follow the pipes which terminate in the seedbed. Openers pulled through the soil make the opening where the seeds are placed. They are typically made of steel in the shape of points, discs or cultivator shovels. Once placed in the seed bed, the air is blown out the opening in the soil and the seed and fertilizer remain. The seeder can then pack the soil tight to retain moisture near the seed and harrow the furrows so the field is not rough.
A typical air seeder has an agricultural commodity cart (“air cart”) comprising at least one, and commonly two, three or more tanks for carrying various agricultural products like seed and fertilizer, which are bolted or otherwise attached to the frame of the commodity cart. The tanks are typically made from either polyethylene, such as found on a CaseIHPrecision Air 3380, or steel such as found on the CaseIH Precision Air 3580.
There is a continued demand for larger capacity commodity tanks. Larger tanks are particularly desirable for wider seeding implements, such as the CaseIH Precision Air 3580. Wider seeding implements are capable of depositing more seed in a single pass. Wider seeding implements will consume seed more rapidly than smaller implements. Hence, there is a general desire to outfit wider seeding implements with larger capacity commodity tanks.
Larger capacity commodity tanks are typically assembled from planar sheet panels. The corners of the tanks are typically formed by separate corner pieces that are attached to a pair of sheet panels. Alternately, it is also common for the ends of adjacent panels to be bent to form an overlapping joint. Regardless of how the corners are made, as the commodity tanks are made larger, the sheet metal panels that collectively form the tanks are consequently larger. One of the drawbacks of larger sheet metal panels is the increased tendency for such panels to warp due to manufacturing processes such as welding or media blasting. One approach to reduce this warping has involved the intentional formation of a bend along the width of the sheet metal panel. Unfortunately, these bends make the connections to mating panels more difficult because basic shapes such as a single overlapping bend or a single bend corner cap cannot be used.